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DYNAMOMETBR.

NQ. 380,294, Patentedlvw 27, lf

N4 PETERS. rhnmmhoxmphu. wamrrgwn, D. C,

UNITED STATES PATENT CHARLES F. MURDOOK, OF DETROIT, MICHIGAN, ASSIGNOROF ONE-HALF TO JONATHAN K. WEBSTER, OF SAME PLACE.

DYNAMOM ETER.

SPECIFICATION forming part of Letters Patent No. 380,294, dated March27, 1888.

Application led September 10, 1885. Renewed November 12, 1887. SerialNo. 254,981. (No model.)

.To @ZZ whom it may concern.-

Be it known that I, CHARLES F. MUEDocK, of Detroit, in the county ofVayne and State of Michigan, have invented new and useful Improvementsin Dynamometers; and I do hereby declare that the following is a full,clear, and exact description thereof, reference being had to theaccompanying drawings, which form a part of this specification.

This invention relates to a new and useful improvement in dynamometers,especially designed to readily ascertain the force required in drivingthe machines in an industrial establishment. The dynamometer hereindescribed belongs to that class in which a spring forms the medium fortransmitting the power, and wherein the state of tension of n saidspring is indicated on a scale on which are marked the degrees of staticforce corresponding to the tension of the springs.

My improvement consists in the peculiar arrangement and construction ofthe parts, all as hereinafter described,and pointed out inthe claims.

In the drawings which accompany this specication, Figure 1 is aperspective view of my improved dynamonleter. Fig. 2 is a similarperspective View, looking at the opposite side, and with some portionsbroken 0H or removed. Fig. 3 is a vertical central section.

A is the counter-shaft from which the power for driving the machinery isobtained. Upon this counter-shaft is secured the hollow shaft B, andupon this is sleeved a loose pulley, C, which is held between twocollars, D E, made fast upon the shaft B. The pulley is provided with ahub, B', and a coil-spring, F, is sleeved upon the hub on one side ofthe pulley, with one end secured to the pulley at a and the other to thecollar E at b.

H is a loose ring seated in an annular groove formed upon the hub of thepulley on the side opposite to where the coil-spring is placed. It isalso provided upon its annular face with a pin or projection, I, andwith a pointer, J, for indicating the position of this loose ring upon ascale, K, with which the adjoining part of the hub of the pulley isprovided.

L is an arm secured to the periphery of the collar D, and adapted toengage upon its free end with the pin I ou the loose ring H, as shown inFig. l.

M is a cap or coverfor the dynaniometerspring F. It is secured in anysuitable manner to the collar E, as shown in Fig. 3, while in Fig. 2 itis shown detached.

In practice, when power is applied to the shaft A and a resistance tothe face of the pulley O, (said resistance being furnished by thedrive-belt) the dynamometer-spring F is put under tension, as it formsthe medium between the power and the resistance. The degree of thetension required to overcome the resistance is indicated by the pointer.I upon the scale K, for it will be seen that the loose ring H, whichcarries the pointer, is turned in a degree corresponding to the tensionof the spring by means of the engagement of the arm L with the pin I.

The loose ring H may be provided with a suitable tension device-such asthe screw c to give it a little friction on its seat, so as to preventits accidental displacement, without, however, offering any resistanceto its turning freely whenever the arm L strikes against the pin I. Thescale K is arranged to indicate the degrees of static forcecorresponding to different states of tension of the spring F.

It is obvious that if there is any uctuation in the power required toovercome the resistance the pointer .I indicates the maximum of power.

The dynamometric pulleyf7 as my device may be properly called, can bereadily applied to counter-shafts of different size by making the boreof the shaft B to correspond; but it is obvious that the shaft B mayform an integral part of the shaft A as far as the operation isconcerned.

The collars D and E are preferably removably secured upon the shaft B bysuitable setserews, or otherwise, so as to admit of adjusting the partsand facilitating the mounting or dismounting of the device. The cap Mprotects the dynamometer-spring from accidental injury.

In adjusting the device for taking a reading the loose ring H ought tobe turned to bring the pin Iin contact with the arm L. Thedynaniometer-spring is preferably of such power that its torsional rangeis only the arc of a circle.

My device is very simple. Its constructive form is very suitable forhaving the pulley Well balanced. It does not form a charge upon thepower. It is of so compact form that it may take the place of anordinary pulley, and it can be read when the machinery is at rest.

What I claim as my invention is- 1. In a dynamometer, the combination ofa loose pulley provided with a hub, of a dynamometer coil-spring placedconcentric to the shaft and forming the medium for transmitting by itstorsional tension the power from the shaft to the pulley, of an annularscale on the hub of the pulley, and of a pointer carried by the shaft,so as to indicate the degree of torsion of the dynamometerspriug, allarranged substantially as described.

2. In a dynamorneter, the combination, with a loose pulley, a shaft, anda coil-spring,which forms the means of transmitting the power from theshaft to the pulley, of au indicator consisting of the arm L, a collaron the shaft, a hub on the pulley, the loose ring H, the pin I, pointerJ, and the annular scale K on the hub of the pulley, all arranged andoperating substantially as described.

3. In a dynamometer, the combination of the loose pulley C, the collarsD E, fast upon the shaft, the coil-spring F, secured at one end to thecollar-E and at the other to the pulley, the arnl L, secured to thecollar D, and the loose ring H, having pointer J and pin I, and theannular scale on the hub of the pulley, all arranged substantially asdescribed.

4. The combination, with the shaft A. the hollow shaft B, loose pulleyC, having a hub, collar E on said hub, and the coil-spring F, placedaround the hub of the said pulley, of the cap M, inclosing said springand collar, substantially as described.

CHARLES F. MURDOCK.

Witnesses:

J. K. WEBsTER, O. F. HEYERMAN,

